Large-scale Multiconfiguration Dirac–Hartree–Fock Calculations for Astrophysics: C-like Ions from O iii to Mg vii

Abstract

Large-scale multiconfiguration Dirac–Hartree–Fock calculations are provided for the n ≤ 5 states in C-like ions from O iii to Mg vii. Electron correlation effects are accounted for by using large configuration state function expansions, built from sets of orbitals with principal quantum numbers n ≤ 10. An accurate and complete data set of excitation energies, wavelengths, radiative transition parameters, and lifetimes is offered for the 156 (196, 215, 272, 318) lowest states of the 2s 22p 2, 2s2p 3, 2p 4, 2s 22p3s, 2s 22p3p, 2s 22p3d, 2s2p 23s, 2s2p 23p, 2s2p 23d, 2p 33s, 2p 33p, 2p 33d, 2s 22p4s, 2s 22p4p, 2s 22p4d, 2s 22p4f, 2s2p 24s, 2s2p 24p, 2s2p 24d, 2s2p 24f, 2s 22p5s, 2s 22p5p, 2s 22p5d, 2s 22p5f, and 2s 22p5g configurations in O iii (F iv, Ne v, Na vi, Mg vii). By comparing available experimental wavelengths with the MCDHF results, the previous line identifications for the n = 5, 4, 3 → n = 2 transitions of Na vi in the X-ray and EUV wavelength range are revised. For several previous identifications discrepancies are found, and tentative new (or revised) identifications are proposed. A consistent atomic data set including both energy and transition data with spectroscopic accuracy is provided for the lowest hundreds of states for C-like ions from O iii to Mg vii.

Benchmarking calculations of excitation energies and transition properties with spectroscopic accuracy of highly charged ions used for the fusion plasma and astrophysical plasma

“…Therefore, these experimental values compiled by the NIST ASD seem to be wrong or at least are affected by large errors. The situation is also well illustrated for the ions in the other L-shell sequences of Belike, [41,42] B-like, [46,47] C-like, [49,50] N-like, [51] F-like, [61,62] and Ne-like. [64] ERMBPT EMCDHF cm -1 The M-shell ions with Z ≤ 30, especially the ions of iron group elements, produce strong extreme ultraviolet (EUV) spectral lines, which are routinely used to measure electron densities using data from, e.g., the SOHO Coronal Diagnostic Spectrometer (CDS), see Ref.…”

“…Using at least one of the three methods (RMBPT, MCDHF, and FAC-RCI), we carried out many theoretical studies of excitation energies and E1, M1, E2, M2 transition rates for Kand L-shell ions with Z ≤ 42, such as the ions in the sequences of H-like, [37,38] He-like, [39,40] Be-like, [41][42][43][44][45] B-like, [46][47][48] C-like, [49,50] N-like, [51][52][53][54][55] Olike, [56][57][58][59][60] F-like, [61][62][63] and Ne-like. [64] It is important to provide atomic data for more than just the levels of the lowest configurations in plasma modeling and diagnostics.…”

Atomic structure and transition parameters of the C-like ion K XIV

“…C-like ions are important for fundamental physics, plasma spectroscopy and astrophysical applications (See [1][2][3] and references therein).…”

“…Recently a lot of works are done in this field: Li et al [2] performed large-scale MCDHF calculations for the n 5 states in C-like ions from O III to Mg VII. Khatri et al [15] calculated relativistic configuration interaction results for the C-like ions Kr XXXI, Rb XXXII and Sr XXXIII using the MCDHF method.…”

Atomic structure and transition parameters of the V XVIII carbon-like ion

“…Jönsson et al (2011) used the relativistic configuration interaction (RCI) method to obtain energy levels, transition rates, hyperfine structure parameters and Landé gJ values in carbon like ions. Recently, Li et al (2022) performed a large-scale Multi-Configuration Dirac-Hartree-Fock (MCDHF) calculations for the n ≤ 5 states in C-like ions from O III to Mg VII.…”